Flight Deck with Deore XT

[Joni WS]

I am converting my mountain bike to a gravel road bike. Would like to change to drop bars. Was wondering if I could use Shimano ST-R500 Flight Deck (8 speed shifters and brake levers) which I took off a road bike with my 8 speed Deore XT derailleurs and V Brakes. If not, do you think it makes sense to get new derailleurs and if so what would be compatible with Flight Deck?

[Joe_W]

The dérailleurs are compatible (all except of the 10 speed Shimano road and MTB stuff is exchangeable as far as I know). The brakes not so much. There is something that can be used for this:
http://problemsolversbike.com/products/travel_agents/

Good luck!

[xerxes]

This might give you a few ideas: http://www.retrobike.co.uk/forum/viewtopic.php?t=94356

You might also want a shorter/higher rise stem, because MTBs have a longer top tube than road frames of an equivalent size.

[Joe_W]

Oh, right: The frame geometries of road and MTB are fundamentally different (steerer angle etc) so you can run into handling problems...

[xerxes]

(11-19-2012, 04:52 AM)Joe_W Wrote:  Oh, right: The frame geometries of road and MTB are fundamentally different (steerer angle etc) so you can run into handling problems...

It's not so much handling problems, more a comfort problem, although, yes, MTB frames generally have shallower frame angles and more "lazy" handling characteristics than an all-out race bike, perhaps more like a tourer.

MTBs also have a higher bottom bracket than road bikes, for added clearence when riding over tree trunks, drop-offs etc.

But when fitting drop bars, as well as being lower, your hands on the drop position will also be 60 to 90mm further forward than where they were on flat handlebars, which with a long top tube and a longish stem, typically 90 to 130mm on MTBs, can make it too much of a stretch.

[RobAR]

You people are confusing me here...
Flight Deck was a shifter / computer Interface (in the 1990's). It was intended for Road gruppos. I hated it as I felt it was TMI. I decide when I need to shift - don't need a computer to decide for me!
The computer head was programed for whatever gear-combo the bike was laden with, and the riders preferred cadence, and rider weight, and Daylight Saving Time... well, maybe not that far but, you get my point.

Joni - if you do not intend to wire up your shifters to a computer head (Flight Deck), what you are attempting is do-able. But you'll want to swap an item or two for best performance.
As Joe mentioned, you will need a 'Travel Agent' to make those R500 levers give you any kind of decent modulation with a V-brake. Brakes are kinda important and it's best to avoid the completly ON or completly OFF thing.

My next question would deal with the Crankset. Up front. Your MTB most likely has a Triple - 3 rings. Will your left shifter do three? 500 was where 105 was just beginning to see triples become popular and you need to look carefully. 105 is now well into the 570 range and 10s. Look for a suffix number after your 500 under the hood. See a ST-500-2 or similar? Current 105 is offered in both Dbl and Trpl.
Your rear XT drlr will play with the right-hand 8 spd 105 as long as you don't change the stack dramatically. 11-32 MTB to 12-24 Road might give you fits keeping everything adjusted for sweet shifts.

Basically - While what you are attempting is possible, Shimano offers more options for turning a Road Bike into a Gravel Road (flat bar) bike. You are kinda going the opposite direction.

I truly hope that this wasn't Too Much Info. My advice, as far as Economics, would be to get something along the lines of a Cyclocross bike and keep the current bike 'as is'. You can quickly sink a lot of money into mods that don't pan out as you expect and then want to kick yourself. Been there. Have the T-shirt.